Mine



Oct 1951 w. N. ENSIGN, JR

MINE

Filed Dec.

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mmm y 2% WWW Patented Oct. 2, 19 51 UNITED STATES PATENT OFFICE .MINE

V Wesley Ensign, Jr., Babylon, N. Y. Application December 19, 1944, Serial No. 568,905 1 Claim. (01. 1 028) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to mines.

A purpose of the invention is to provide a device which, when used in conjunction with or as a part of an explosive mine, will make removal of the mine more difiicult by causing it to explode if the mine is tilted or moved.

Another purpose is to provide a tamper proof mine that can be disarmed only by those having the combination number applicable to the mine.

Other purposes will become apparent from the following description.

Reference is now had to the drawings, in which similar reference characters refer to similar parts throughout the'several figures and in which:

Figure l is a diagrammatic partly cutaway view of a land mine casing showing one form of the tamper proof device, including combination adjusting switch,

Figure 2 shows a diagrammatic partly cutaway view of a land mine casing showing another form of the tamper proof device, including pull adjusting switch,

Figure 3 is a partly diagrammatic and partly sectional view of a marine mine casing showing the combination adjusting switch and mercury contact switch.

Figure 4 is a view of a portion of the mine casing of Figure 1 as seen from the outside, showing the binding posts and external combination knobs and graduations, and

Figure 5 is a plan view of the top of the pendulum switch.

In connection with the use of mines, whether of the land or marine type, it is desirable to prevent the removal of the mine until it has either been exploded by contact with an enemy land or sea vehicle, or has served to prevent the enemy from traversing the area covered by the mine field. This invention shows a means by which removal of mines is rendered quite difiicult.

In Figure 1 the tamper-proof device is shown inside a land mine I of the pressure type which is designed to explode when sufiicient pressure is exerted upon the pressure receiver 2. The rest of the usual internal structure of the pressure type mine is not shown in the drawing. Within the mine body a pendulum 3 is suspended in a chamber 4, the pendulum being suspended through an aperture 5 in the platform 6 from a head 1 which is fastened to or made integral 2 with the pendulum shaft I 8. The platform 6 and the sides of the chamber 4 are preferably made of material which does not conduct electricity so that elements mounted on or touching it need not have individual insulators. The pendulum is provided with a spherical weight 8 at its lower end and a metal contact disk 9 at its upper end. A metal contact ring I0 is positioned as indicated. concentric and coplanar with contact disk 9.

The contact ring It bears a, number of metal contact points 24 spaced around its inner surface with points projecting inward towardthe contact disk 9. The distance separating the contact disk 9 from the contact points 24 is small so only a little movement is needed to bring them together. When the pendulum is centered, none of the contact points 24 of the contact ring 10 are in contact with the contact disk 9. The contact disk 9 of the pendulum 3 is connected by pigtail l1 and wire 0 to one terminal of an electric battery l9 and the other terminal of the battery is connected by the wire :1 to one terminal of an electric detonator or primer 2!]. The contact ring I0 is connected by wire a to contact arms H, 12 and I3, each of which is adapted to be: turned so as to be connected with its own con-- tacts A, B, C or D. Thus, contact arm II can. be turned to connect with either contact A, B,. C or D, as shown in the drawing. Similarlycontact arm I 2 has its own set of 4 contacts, and. so has contact arm I3.

together and to wirea. Likewise, all the contact points except one in each group of four, are connected together and to wire e, as shown. The contacts which are connected to wire e will be; designated as live contacts while those which, like contact B of contact group I6, or contacts A and B of contact groups I 5 and M respectively, are not connected to anything, will be designated as dead contacts. Thus, if any contact arm is connected to any live contact, then there is a continuous electrical connection from the contact ring In through wire a, through a contact arm and the live contact, through wire e to one terminal of the detonator 20. From the other terminal of the detonator, there is a continuous electrical connection through wire d, through battery I9, and through wire 0 and pigtail I! to the metal contact disk 9. If contact disk 9 is brought into contact with any contact on contact ring it), by tilting the mine causing the pendulum to tilt, then the electrical circuit is completed, permitting current to flow through the primer 20, exploding it and the mine. a

It is apparent thus that if each contact arm It will be seen in the: diagram that all the contact arms are connected.

3 on a dead contact the electrical connection will not be continuous from the contact ring to the electric detonator through wires a and e. Thus, even if the pendulum is tilted to bring the contact disk 9 into contact with the contact points 24 no current will flow through the primer and hence it will not explode the mine. It follows thatthe tamper proof device is in the safe position when all contact arms are on dead contacts. The safe positions may be denoted by a combination showing the numbers of the dead contacts. For example the safe combination in Figure 1 would be BAB. The fsafe combination for each mine could be stamped or printed upon the surface of the mine in some codethat would be known only to those who set the mines and remove them. Thus friendly personnel would be able to disarm thetamper proof device before removing or moving the mines.

While the anti-tamper device is in the safe position, :the mine will not explode by merely tilting it, but the mine cannot be installed and set .untilthe pendulum is centered so thecontact disk-3 is not in contact withthe contacts, 24 on coptact ring Ill. To determinewhen these two members are out of contact two external binding posts ;;2i and 22 are mounted on th mine and insulated therefrom. These are connected resp tively to one side of the detonator -20 and tosthe contact ring til-as shown, and a voltmeter 23;-is connected-across the binding posts,.-having ayoltage range suitab1e for measuring voltage ofbattery-lt. ,Starting ,withthe tamper proof deviceinthesafe position, the mine is then leveleduntil the voltmeter .23 shows a zero voltage reading. This .indicates that contact disk 9 is notinpontact with any of contacts 24. .It is then .known that the mine is level and the contactarms -H,l2, .and'l3 can safely-be, turned to live contacts. It is thenready toiexplode if tilted A outv of level. The voltmeter23 maybe a portable oneiand. one meter used for .-all,the mines:.to,,be laidrby, themine laying squad.

Jiigure 2 .ishowsa modified form of the device of Figure 1, in .which the pendulum switch is retained but the combination adjusting switch omitted, and another arrangement substituted therefor. In thedrawing, the wire. 1 leadsifrom thecontactring of the pendulumswitch to one terminal of thebattery'.IBHandtheother battery terminalconnects by meansoi .wire 47 tonne terminalof electric detonator 2,0. 'Theother terminal of thedetonator Zilconnects by wirei to one terminal of aspring jack 3!! mountedon the side wall ofthe pendulum chamber :4, said jack=having two metal spring contactors .25.and 26 disposedsideby sideand making-contact with each-other by spring action. The otherspring contactor 26 has its fixed base connected by wired to:the pigtail l'l andthenceto the contact disk 9. A plug 2? having a non-conducting upper layer;29 and-a conducting :metallower layer :28 is-adapted to be insertedbetween the prongs-25 and 26 of the jack .353 and thus to separate them *wheninserted. The conductinglower portion-28 of the plugi2l makes contact with the prongZB of the jack 30 when inserted therein and a wire 70 is connected to said conducting portion. The other end of wire k leadsthrough a-baffie 56 and an aperture 3! in the mine casing and thence and a pull ring 34 is attached to the free end of said cord 33. It is apparent thatwhen the plug 21 is inserted in the jack 3D a pull on the pull ring 34 will pull the plug out of the jack.

,The mine may be shipped and stored with the plug 21 inserted in the jack 30 thus keeping the prongs 25 and 26 from making electrical contact with ,each other, although the conducting portion 28 of the plug makes contact with the prong 26 ,of thejack. Theexternal end of wire k may be insulated and left attached by adhesive tape to the outside surface of the mine together with the ring 34. The meter 23 may be packed separately for safety from rough handling and may be used by the mine laying detail for setting a number of minessince itis only-used for setting the mines. When the mine isto besetin a mine field, it is .placed in position and-then the voltmeter 23 is connected to the binding post 32 and the wire .lc. The plug 2! has not yet been removed from the jack 38. It is thus seen that if themineis not level, the pendulum is :tilted and the contact disk 9 is in contact with one or more of the contact points 24 mounted on the contact ring Ill. Hence there is .a continuous electrical circuit through the battery I 9, thevoltmeter 23, one side -28 of the plug-Z'Lone prong 250i thejack 30, and through the pendulum switch. The meter 23 gives a reading showing theabovecircuit ,is complete. The mine is then tilted or leveled until the rneter reads, zero voltage, indicating that thependulum switch is-open. Since-the mine is new level, themeterjs disconnected and'thepull ring 4 pulled so as to pull the plug 21 out of the jack 30, whereupon the contact prongs 25 and 28 sprin tqgether into electrical contact with each other. This places-the battery l9 in a series circuit with the detonator and thecircuit is only openat the pendulum switch since the 1 contact disk 9 is not touching any-of the contact points 24. If the-mine should now;be' tilted or moved, the relatively heavy pendulum weight ;8 will swing relativelto the rest of themine, andthe contact disk 9 will touch one of the contact points 24, closingthe series circuit whereupon current will flow from the battery 1-9 through the electric detonatoriil, exploding it andhence setting off 3 the mine.

Thus the device effectively prevents removal of the mine until it isexploded'by pressure or to the outside of'the mine whereit isconnected to'one terminal of ajvoltmeter 23 ,of a range suitable to measure thevoltage of battery IS. The other terminal of the voltmeter .23 is connected by wire mto a'bindingpost'32-mounted on the other external means. Once-the mine has been installed, the wire it may be cut close to :the aperture ,3l and theend pushed back inside the mine so'it cannot-be reached.

Figure-3shows a sectional view of afioating marine mine which is designed to explode on contact .with a passing ship. To prevent removal. of the mine, it is also equipped :with the safety device shown. In the drawing a marine mine..35 hasa platform or bulkhead 36 dividing its interior into anupper chamber 31 and a lower 1 chamber 38. The outer mine surface of the chamber '38 is punctured with a multitude of holes 54 so as toallow the water to entirely fill the lower chamber 38 when the mine is placed in the water. A hollow tube 49 connects to a centralapertureg il in the platform 36 by means of-a funnel shaped portion 39 and leads through two successive u-shapedtube bends 42 and-5 33 of small cross section, forming a gooseneck as shown, into a small diameter upright tube 44 having at its upper extremity an air chamber 45. The tube bend 43 contains two electric contacts 46 and 41 positioned near each other but not touching, and they are connected to the outside of the tube by wires leading through the tube 40 and insulated thereupon. A quantity of liquid mercury 48 occupies the tube bend 43, its quantity being sufiicient to close off the tube comprising the U-shaped portion 43 so as to prevent air from passing through the tube past the mercury.

One contact 46 is connected by wire 49 to one terminal of an electric detonator 20, the other terminal of which is connected by wire 59 to one terminal of an electric battery 19. The other terminal of the battery is connected by wire 5| to the moving contact arms Ii, I2 and 13 of a triple combination switch 52, all contact arms being connected together electrically. Each contact arm is adapted to make contact with any one of four contact points, one of which is dead as heretofore explained, and the other three contact points are connected together and denoted live contacts. All three sets l4, l5 and I6 of live contacts are connected together and connected by wire 53 to the contact 4! in the tube bend 43.

When the mine is lowered into the water, it seeps through the holes 54 into the chamber 38, up through the funnel 39 and tube 40 compressing any trapped air in tube bend 42 down into tube bend 43, forcing mercury 48 up into tube 44 and thus breaking the electrical connection between the two contacts 46 and 41. The air in the chamber 45 is compressed by the upward movement of the mercury in the tube 44.

Since the battery, detonator, combination switch and mercury switch are all connected in series, it follows that the three movable arms of the combination switch 52 must be set on dead contacts while the mine is being placed in the water up to the water level 55. When this has been done, the mercury switch is open due to the water pressure as already explained. Then the combination switch 52 is set to live contacts. If the mine should now be lifted out of the water, the water drops out of the chamber 38 and funnel 39. The air pressure in chamber 45 forces the mercury down into the tube bend 43 so that it makes contact between contacts 46 and 41, thereby closing the electrical circuit and causing cur rent to how through the electric detonator 20 exploding the mine.

While the foregoing specification sets forth the invention in specific terms, it is to be understood that numerous changes in the shape, size, ar= rangment and materials may be resorted to without departing from the spirit and scope of the invention as claimed hereinafter.

I clainli v A land mine having a casing, electrical antidisturbance means including electrically operable explosive means, a source of electric current associated with said explosive means for igniting same, a circuit including said explosive means, said current source and a normally open inertiasensitive anti-disturbance switch arranged to close upon substantial physical disturbance of said mine, means external to said mine for indicating the circuit condition of said anti-disturbance switch, additional switch arming means comprising a pair of cooperating switch contact members spring-urged toward each other, an insulated member between said contact members for rendering said anti-disturbance means inoperative to ignite said explosive means whereby said mine may be placed in position in disarmed condition, and a flexible tension member operable from the exterior of said casing for pulling said insulating member from between said contact members to arm but not thereafter to disarm said mine.

WESLEY N. ENSIGN, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 913,524 Leon Feb. 23, 1909 1,214,771 Fortier Feb. 6, 1917 1,286,705 Meskill Dec. 3, 1918 1,390,768 Dorsey Sept. 13, 1921 1,405,260 Beavers Jan. 31, 1922 1,407,653 Hammond Feb. 21, 1922 1,471,628 Palmer Oct. 23, 1923 1,519,303 Gross et a1 Dec. 16, 1924 1,901,185 Nelson Mar. 14, 1933 FOREIGN PATENTS Number Country Date 26,734 Great Britain 1907 29,013 France 1925 594,479 France 1925 541,624 Great Britain 1941 

